I would think it depends...
What formation will this [basic spearman] be fighting in? A dense phalanx (pikes)? A more loose formation? A skirmisher role? Also, what level of tech is available (any/all?) and what is the logistical and financial situation supporting the soldier? No one really wants to head into battle with cheaper gear, but sometimes they have to so more men can be fielded. Also, I'd assume, carrying extra stuff on long ass marches sucks. And what climate will they be in?

That would affect all the things that follow on the list.

A good general-purpose [basic spearman] would be, I'd say:
A. Rectangular Shield
B. Dagger
C. (maybe 1 or 2 javelins)
D. basic mail shirt (sleeves/no-sleeves/whatever minor modifications fit)
E. actually, the above guy is already kind of a 'heavy' spearman. I guess you could up-armor a pikeman for a "wall of spears and steel" effect...? It'd be a pain to march him around, tho.

The main area the spear -man will be fighting is in Cities/around Cities with some on Campaign. The level of tech is slightly schizo due to most nations being Late Classical (600ADish) to Early Medieval. The financial situation would be mainly well off (not really rich) city states and most of their weapons use bronze/iron (a little steel but that has to be imported in). The Climate is temperate.

Well, you could use the hoplite model. You make it sound like the primary combatants are city-states.

If you want an early medieval bent, here's an excerpt from the Pracepta Militaria regarding the Byzantine heavy infantry's equipment:

Nikephoros Phokas said:

Short tunics reaching to the the knees are to be required, made of cotton or coarse silk. Their sleeves have to be short and broad with slits up to the shoulder joints so that they can put their arms through easily and comfortably fight. Their sleeves should be fastened with loops and buttons back on the shoulders. If possible, let them also have short footwear folded up to the knees or unfolded up to the thighs, or else sandals, that is mouzakia, or those called tzerboulia in colloquial speech. They must have thick caps of felt to be fastened over their heads with bands of cloth1, and certainly swords girded at the waist, axes or iron maces, so that one man fights with one weapon, the next with another, according to the skill of each one. They should all have slings in their belts. Their shields must be no less than six spithamai2 and, if possible, should be even larger. Their spears must be thick and sturdy, from twenty five to thirty spithamai3 in length. Their points should be fit for the task, as should their fastenings.

Click to expand...

1 This would resemble a turban2 Six Spithamai is about 120 cm. Assumed to be a "kite" shield, made of wood and covered with either leather or linen, based off of contemporary illustrations.3 An improbable length, up to 5 to 7 meters. It it's likely a scribing error. A more probable length can be found in the Sylloge Tacticorum, where spears are recommended to be eight or ten cubits long, or 3.7-4.7 meters. For reference, pikes from the 16th century were about 4.5 to 5.5 meters long. These are not short spears by any means.

For context, medieval Roman heavy infantry isn't as "heavy", aside from foreign mercenaries or the professional, elite Tagmatic units, compared to Hoplites. They are not the affluent citizen-militia of the Greek city states, but typically drawn from the poorer Armenian frontiersmen, with humble means. However, they are pretty much the model for the "heavy" spearmen of the day. Almost all foot infantry were equipped in a more or less similar fashion, though the specifics differed: heavy cloth for armor, shields, a polearm, and a side-arm of some description. Metal armor was a rarity, but an army that had defeated another might be swagged out with a mish-mash of "better" gear pillaged from an enemy's corpse. In such a case, you might find some of the men wearing maille, brigandine, or lamellar stripped from a richer soldier. Only an elite foot unit, such as Huscarls, the aforementioned Tagmatic troops, men-at-arms, etc are going to muster with such expensive gear.

The main area the spear -man will be fighting is in Cities/around Cities with some on Campaign. The level of tech is slightly schizo due to most nations being Late Classical (600ADish) to Early Medieval. The financial situation would be mainly well off (not really rich) city states and most of their weapons use bronze/iron (a little steel but that has to be imported in). The Climate is temperate.

Click to expand...

Cities seem like they'd be a pain for heavy infantry, actually.

You form up in your unbeatable shield wall or whatever, only to have an enemy unit come up through an alley and flank you or learn that the enemy is on the roofs throwing stuff at your head. I will also note that if the infantry is actually going to get into buildings, the environment may interfere with their ability to make use of longer weapons.

With that in mind, I'd like to suggest a good helmet and some protection for the back and sides. I'll leave it to the people who know what they're talking about to suggest what would qualify though.

The cities they are fighting in they have the home field advantage. Generally if the City States are invading another nations cities they'll rely on their allies who have better troops for city fighting while the CS troops hold the line against counter attacks.

Uh, hoplites should not be all that disadvantaged in a city fight. Sure, their long spears might prove to be a liability if the buildings are densely packed, but even the medieval roman spear/pikeman I outlined above comes with effective sidearms and slings to provide longer range missile fire.

Even then, it's a general tendency that if the walls fall and there is no central citadel, the city is as good as lost.

Uh, hoplites should not be all that disadvantaged in a city fight. Sure, their long spears might prove to be a liability if the buildings are densely packed, but even the medieval roman spear/pikeman I outlined above comes with effective sidearms and slings to provide longer range missile fire.

Even then, it's a general tendency that if the walls fall and there is no central citadel, the city is as good as lost.

Click to expand...

I'm more concerned with the movement, to be honest. A lot of formations are very good to the front but weak to the rear, for instance. An enemy that knows the terrain, in particular a maze of passages, can use that knowledge to flank forces and defeat them in detail before allies can arrive. It would of course be bloody for both sides.

I'm also coming from this from an Asian history perspective. Japanese defenses in particular were frequently planned around this concept. I know this is a European setting, so that might not be applicable here, but there's nothing mechanically keeping such an arrangement from coming about.

General Scrage:

The cities they are fighting in they have the home field advantage. Generally if the City States are invading another nations cities they'll rely on their allies who have better troops for city fighting while the CS troops hold the line against counter attacks.

Click to expand...

So, they're the defenders?

That changes things. Heavy infantry to block key passages, anything a sizable force could fit through, with the largest shields and heaviest armor they can get and reasonably use.

I'm more concerned with the movement, to be honest. A lot of formations are very good to the front but weak to the rear, for instance. An enemy that knows the terrain, in particular a maze of passages, can use that knowledge to flank forces and defeat them in detail before allies can arrive. It would of course be bloody for both sides.

Click to expand...

Local knowledge is always a strong advantage, make no mistake, but it would affect any troops not native to that particular city.

I'm also coming from this from an Asian history perspective. Japanese defenses in particular were frequently planned around this concept. I know this is a European setting, so that might not be applicable here, but there's nothing mechanically keeping such an arrangement from coming about.

Click to expand...

That's mostly during a fighting retreat to an inner wall or citadel, though.